This invention relates generally to emergency wash equipment for flushing irritants from the eyes and/or face of an individual, particularly such as a person working in an industrial or laboratory environment. More specifically, this invention relates to an improved wash station of relatively simplified construction to provide a gentle yet generous and substantially full face flushing flow of water, wherein water inlet and drain flows are effectively separated to prevent inadvertent mixing during failure mode conditions.
Emergency wash stations are generally known in the art for use in flooding the eyes and/or face of a person with a substantial flushing flow of fresh water. Such stations are commonly used in industrial and/or laboratory environments wherein irritants such as liquid or solid chemicals, fumes, and other toxic substances are present. The wash station typically includes one or more spray nozzles for passage of fresh water to flush irritants which may have contacted the eyes and/or face of a person. An easily operated valve mechanism is normally provided to facilitate water supply connection to the spray nozzles, and a drain basin is normally present to collect and drain the flush water and accumulated contaminants.
In the past, emergency wash stations of the above-described type have generally utilized spray nozzles disposed within or slightly above the drain bowl, and supplied with water via one or more water supply pipes extending into the interior of the drain bowl. See, for example, U.S. Pat. Nos. 3,599,251; 3,629,876; 2,482,960; 2,458,876 and 4,012,798. However, while these wash stations perform satisfactory during normal operation, the positioning of a supply pipe within the drain bowl undesirably permits intermixing of fresh supply water with contaminated drain water during certain failure mode conditions. In particular, in the event of bowl flooding, contaminated waste water within the bowl can backflow into the water supply pipe when certain flow conditions are present, resulting in potential contamination of the fresh water supply. The consequences of such contamination can be significant, depending upon the particular irritant substances which may be present within the flooded drain bowl.
Alternative wash station designs have utilized external plumbing connections supplying water to spray nozzles located typically above opposite sides of an underlying drain bowl. See, for example, U.S. Pat. Nos. 2,999,248 and 3,413,660. However, these networks require relatively complex plumbing arrangements including separate pipe connections to the spray nozzles at opposite sides of the drain bowl. Moreover, the laterally spaced arrangement of the spray nozzles requires nozzle orientation for water discharge at relatively low trajectories in order to achieve substantially full face flush coverage during operation. However, with low spray trajectories, variations in water supply pressure can significantly alter the desired spray pattern, resulting frequently in inadequate face coverage during low pressure conditions or in water overspray during high pressure conditions. Accordingly, such station designs have often included relatively costly pressure control regulator devices to prevent malfunction in response to variable water supply pressures.
The present invention overcomes the problems and disadvantages of the prior art by providing an improved wash station having a spray manifold mounted above and at opposite sides of a drain bowl, and connected by a relatively simple external plumbing fitting to a fresh water supply. The present invention fulfills these needs and provides further related advantages.